Before the invention is described in detail, it should be mentioned that the technique for chip removing machining of, above all, workpieces of metal is quickly developing. When blanks or workpieces were previously machined to finished products having some complexity, such as engine components, vehicle and craft components, machine parts, etc., the manufacture was carried out in a plurality of steps or stations, which individually required separate set-ups of one and the same blank. For instance, a first machining could be one or more turning operations. If the detail also required different forms of recesses, such as key grooves or bar grooves, the same was moved to a new set-up of another station, where milling followed. Should the same in addition be provided with different forms of holes or ducts, transfer was carried out to an additional set-up of a drilling machine or drilling station. More recent, machines were developed in which a magazine is included having a large number of tools, each one of which can be picked out of the magazine and brought to an active state for machining, and which after accomplishing the machining is brought back to the magazine to be replaced by another tool.
In order to make the manufacture more effective and reduce the time for, as well as the cost of, the machining, universal machines have recently been developed in the form of so-called MultiTask machines, in which a large number of program-controlled tools are included, which are flexibly movable in space and capable of executing multiple machining operations, such as turning, milling, drilling, grinding, etc., without the workpiece having to be removed from the machine or the set-up thereof in the same, and in which the need for time-consuming tool exchanges is reduced to a minimum. In such universal machines, partly new requirements are made on the tools in question, not only in respect of their capacity to execute conventional as well as new machining operations, but also in respect of the accessibility of the tools so far that the individual tools should be able to move in complicated paths of motion within a limited space and in spite of this be able to come into contact with those parts of the blank being machined which are difficult to access. This applies not at least to milling cutter tools, e.g., of the type that is used for the milling of notches of different types.
A previously known milling cutter tool is described in SE 0400384-4 (publication number 526.644). This known tool includes a cutting body, which has two diametrically opposed sets of teeth, which are orientated perpendicularly to the neutral plane of the cutting body, and situated in pairs right in front of each other. This means that each pair of teeth will operate in one and the same notch in the form of a straight notch, the two teeth of the pair going alternately in engagement with the workpiece after each half a revolution of rotation of the tool. This tool is useful for a plurality of different milling operations, but not for gear hobbing.
The present invention aims at obviating the above-mentioned shortcoming of the previously known milling cutter tool and at providing a milling cutter tool and a cutting body associated therewith, which are suitable for gear hobbing, in particular in MultiTask machines.
An object of the invention to provide a milling cutter tool, the cutting body of which is designed in such a way that the tool can, by simple feeding motions, be utilized for gear hobbing, in particular for the creation of bar grooves or splines in shafts or shaft spigots having a rotationally symmetrical, usually cylindrical shape.
Another object of the invention is to provide a tool having great accessibility so far that it should be possible to feed the tool by simple geometrical motions and to bring the tool quite close to shoulders and the like, in particular in order to optimize the length of milled bar grooves. In addition it should be possible to utilize the cutting body of the tool for up milling as well as down milling.